22 research outputs found
Estudio de la adsorción de HPOMs sobre alúmino-silicatos naturales modificados para su aplicación en reacciones limpias de oxidesulfurización
Se investiga el grado de interacción y adsorción de Mo a partir de iso y heteropolimolibdatos soportados en alúminoslicatos naturales (caolines y zeolitas) puros y modificados. Se presenta la caracterización y evaluación preliminar de estos sistemas en la reacción de oxidación selectiva de difenilsulfuro con peróxido de hidrógeno. Los minerales fueron sometidos a diferentes pretratamientos fisicoquímicos, para ser utilizados como soportes catalíticos. Con el objetivo de mejorar la adsorción de POMs y HPOMs sobre la superficie del mineral, se funcionalizó la misma con diferentes aminosilanos. Todos los materiales fueron caracterizados por diversas técnicas fisicoquímicas convencionales como DRX, y FTIR y térmicas. Los ensayos de TPR permitieron analizar el tipo de interacción de los HPOMs en cada superficie. La reacción de oxidesulfurización se realizó en “batch” a 75°C, empleando H2O2 como oxidante “limpio” y acetonitrilo como solvente. La mayor adsorción de Mo alcanzó un 11% en la superficie de caolín modificado y funcionalizado y 4% en las zeolitas. Las conversiones de difenilsulfuro obtenidas fueron superiores al 95% en los sistemas conteniendo POMs, con elevada selectividad a difenilsulfona.The degree of interaction and adsorption of Mo is investigated from iso- and heteropolymolybdates supported in pure and modified natural alúminoslicatos (zeolites and kaolins). Also, evaluation of these systems in the reaction of selective oxidation of diphenyl sulfide with hydrogen peroxide is presented. Minerals were subjected to various physico-chemical pretreatments, for use as catalyst supports. With the aim of improving adsorption of POMs and HPOMs on the mineral surface, it was functionalized with different aminosilanes. All materials were characterized by various physicochemical techniques such as conventional XRD and FTIR and thermal analysis. TPR tests helped analyze the type of interaction with HPOMs on every surface. The catalytic tests were performed in batch at 75 °C, using H2O2 as clean oxidant and acetonitrile as solvent. In functionalized systems the amount of Mo adsorbed reached close to 11% for acid metakaolins and 4% for zeolites. Diphenyl sulfide conversions obtained were above 95%, with high selectivity to diphenyl sulfone
MVMoO7 substituted phases (M=Fe, Cr): structural stability, reducibility and catalytic properties in methanol oxidation
Structural, spectroscopic and thermal properties of MVMoO7 (M= Fe, Cr) phases, of potential interest in the catalysis field, are studied by means of X-ray Powder Diffraction XRD, Fourier Transformed Infrared Spectroscopy FTIR, Electronic Scanning Microscopy and X Ray Energy Dispersive Scattering Micro-Analysis SEM-EDS and Temperature Programmed Reduction TPR techniques. Thus, the formation of a triclinic solid solution in a complete range of composition is supported by a little M(III) size difference (about 5 %). In relation to the thermal reduction behaviour, iron is the unique reducible trivalent species. The reduction products of the Fe-Cr solid solution seem to be governed by the structural arrangement and particularly by the presence of M2O10 dimmers. The results are analyzed and compared with TPR data of MoO3, V2O5, M2O3,M2(MoO4)3 and MVO4 (M= Fe, Cr) binary and ternary systems. For the Fe-end member of the isomorphous series, a part of iron remains unreduced as FeV2O4–spinel phase at 1000oC whereas (V,Cr)2O3 is the final oxidizing product for the Cr-end member. However, the (Fe0.5Cr0.5)VMoO7 reduction occurs through the formation of FeMoO4 intermediate, affecting the Mo(VI)-Mo(IV)-Mo stability field and the V(V)-V(III) reduction steps. Finally, MVMoO7 (M= Fe, Cr) phases are chemically proved in the methanol oxidation reaction by Transients Study and the relationships among structural and chemical features and the catalytic behaviour are analyzed and discussed.Se reportan las propiedades estructurales, espectroscópicas y térmicas de fases de fórmula:
MVMoO7 (M= Fe, Cr), de potencial interés en el campo de la catálisis. El estudio se realizó mediante técnicas como Difracción de Polvos por Rayos X, (DRX), Espectroscopía de Infrarrojo por Transformada de Fourier, (IRTF), Microscopía electrónica de Barrido y Microanálisis por Energía Dispersiva de Rayos X, (MEB) y técnicas de reducción térmica programada (RTP). La formación de una solución sólida triclínica en un rango completo de composición depende de una pequeña diferencia (5%) en el tamaño de M(III). Respecto al comportamiento en la reducción térmica, el Fe(III) fue la única especie trivalente reducible. Los productos de reducción de la solución sólida Fe-Cr parecen depender del ordenamiento structural y especialmente de la presencia de dímeros M2O10. Los resultados fueron analizados y comparados con datos de RTP de sistemas binarios y ternarios como MoO3, V2O5, M2O3, M2(MoO4)3 y MVO4 (M= Fe, Cr). Para el miembro final de Fe de la serie isomorfa, una parte del Fe permanence sin reducir como la fase espinela FeV2O4 a 1000 ºC, mientras que (V,Cr)2O3, es el último producto oxídico para el miembro final de Cr. Sin embargo, la reducción de (Fe0.5Cr0.5)VMoO7 ocurre a través de la formación del intermediario FeMoO4, afectando el campo de estabilidad de Mo(VI)-Mo(IV)-Mo y las estapas de reducción del V(V)-V(III). Finalmente las fases MVMoO7 (M= Fe, Cr) fueron evaluadas en la reacción de oxidación de metanol mediante el Estudio de Transientes. Se analizó y discutió el comportamiento catalítico en relación a las propiedades químicas y estructurales.Centro de Investigación y Desarrollo en Ciencias AplicadasCentro de Química Inorgánic
Investigación de la resolución cinética eco-compatible de R/S-ketoprofeno
Se llevó a cabo la esterificación de R/S-ketoprofeno empleando metanol, etanol, 1- y 2-propanol como reactivos y solventes catalizada con el biocatalizador comercial Novozym® 435. Se estudió la interacción de los alcoholes con el biocatalizador mediante diversas técnicas espectroscópicas. Los resultados evidenciaron la disolución del soporte polimérico, la pérdida de proteína activa, la fuerte adsorción de los alcoholes, la modificación de la estructura secundaria de la proteína y el alisado de la estructura interna de las esferas de biocatalizador.Facultad de Ciencias Agrarias y Forestale
Investigación de la resolución cinética eco-compatible de R/S-ketoprofeno
Se llevó a cabo la esterificación de R/S-ketoprofeno empleando metanol, etanol, 1- y 2-propanol como reactivos y solventes catalizada con el biocatalizador comercial Novozym® 435. Se estudió la interacción de los alcoholes con el biocatalizador mediante diversas técnicas espectroscópicas. Los resultados evidenciaron la disolución del soporte polimérico, la pérdida de proteína activa, la fuerte adsorción de los alcoholes, la modificación de la estructura secundaria de la proteína y el alisado de la estructura interna de las esferas de biocatalizador.Facultad de Ciencias Agrarias y Forestale
Investigación de la resolución cinética eco-compatible de R/S-ketoprofeno
Se llevó a cabo la esterificación de R/S-ketoprofeno empleando metanol, etanol, 1- y 2-propanol como reactivos y solventes catalizada con el biocatalizador comercial Novozym® 435. Se estudió la interacción de los alcoholes con el biocatalizador mediante diversas técnicas espectroscópicas. Los resultados evidenciaron la disolución del soporte polimérico, la pérdida de proteína activa, la fuerte adsorción de los alcoholes, la modificación de la estructura secundaria de la proteína y el alisado de la estructura interna de las esferas de biocatalizador.Facultad de Ciencias Agrarias y Forestale
Composites based on modified clay assembled Rh(III)–heteropolymolybdates as catalysts in the liquid-phase hydrogenation of cinnamaldehyde
New composites based on the [RhMo6O24H6]3− (RhMo6) heteropolyanion supported on pillared (PILC), heterostructured (PCH) and functionalized(PILC-F) and (PCH-F) systems based on clays were prepared, characterized and tested as catalysts in the liquid-phase hydrogenation of cinnamaldehyde. The original phases and supported systems were characterized using several techniques such as powder X-ray diffraction (XRD), scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM–EDS), Raman microprobe studies, X-ray photoelectron spectroscopy (XPS), thermogravimetry and differential thermal analyses (TG-DSC), temperature programmed reduction (TPR), and textural analysis (BET method), which confirmed their functionalization, physicochemical modification and the nature of Mo adsorbed species. Active acidic, basic and redox sites were determined by temperature programmed surface reaction (TPSR). Mo loading reached 7 wt% for the system RhMo6/PCH-F and 3 wt% for the system RhMo6/PILC-F, while unfunctionalized clay systems showed a value of 1 wt% of Mo. The catalytic performance showed that PCH-based composites were the most active and reached up to 56% conversion at 360 min of reaction when tested in liquid-phase cinnamaldehyde hydrogenation. The selectivity for all the systems was mainly toward hydrocinnamic aldehyde (HCAL) and reached 77% for the RhMo6/PCH-F catalyst at 25% conversion.Facultad de IngenieríaCentro de Investigación y Desarrollo en Ciencias AplicadasFacultad de Ciencias Exacta
Investigación experimental y teórica de la resolución cinética ecocompatible de R/S-ketoprofeno
Se llevó a cabo la esterificación de R/S-ketoprofeno empleando metanol, etanol y 1-propanol como reactivos y solventes catalizada con el biocatalizador comercial Novozym® 435. Se estudió la interacción de los alcoholes con el biocatalizador mediante diversas técnicas espectroscópicas. Los resultados evidenciaron la disolución del soporte polimérico, la pérdida de proteína activa, la fuerte adsorción de los alcoholes, la modificación de la estructura secundaria de la proteína y el alisado de la estructura interna de las esferas de biocatalizador. Sin embargo, ninguno de estos inconvenientes influye en la actividad del biocatalizador. Finalmente, los cálculos teóricos demostraron que el metanol ejerce impedimento estérico y electrónico en la etapa de coordinación del R/S-ketoprofeno con la tríada catalítica.Methanol, ethanol and 1-propanol were used as reactants and solvents in the esterification of R/Sketoprofen catalyzed with Novozym® 435. The interaction of the alcohols with Novozym® 435 was studied at a molecular level through various spectroscopic techniques. The results evidenced the dissolution of the polymeric support, loss of active protein, strong adsorption of the alcohols, modification of the secondary structure of the protein and smoothing of the inner structure of the biocatalyst’s beads. Nevertheless, none of those drawbacks influences the biocatalyst activity.
Theoretical calculations demonstrated that methanol introduces steric and electronic hindrance from the step of the coordination of the R/S-ketoprofen with the catalytic triad.Centro de Investigación y Desarrollo en Ciencias Aplicada
Canagliflozin and Cardiovascular and Renal Outcomes in Type 2 Diabetes Mellitus and Chronic Kidney Disease in Primary and Secondary Cardiovascular Prevention Groups
Background: Canagliflozin reduces the risk of kidney failure in patients with type 2 diabetes mellitus and chronic kidney disease, but effects on specific cardiovascular outcomes are uncertain, as are effects in people without previous cardiovascular disease (primary prevention). Methods: In CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation), 4401 participants with type 2 diabetes mellitus and chronic kidney disease were randomly assigned to canagliflozin or placebo on a background of optimized standard of care. Results: Primary prevention participants (n=2181, 49.6%) were younger (61 versus 65 years), were more often female (37% versus 31%), and had shorter duration of diabetes mellitus (15 years versus 16 years) compared with secondary prevention participants (n=2220, 50.4%). Canagliflozin reduced the risk of major cardiovascular events overall (hazard ratio [HR], 0.80 [95% CI, 0.67-0.95]; P=0.01), with consistent reductions in both the primary (HR, 0.68 [95% CI, 0.49-0.94]) and secondary (HR, 0.85 [95% CI, 0.69-1.06]) prevention groups (P for interaction=0.25). Effects were also similar for the components of the composite including cardiovascular death (HR, 0.78 [95% CI, 0.61-1.00]), nonfatal myocardial infarction (HR, 0.81 [95% CI, 0.59-1.10]), and nonfatal stroke (HR, 0.80 [95% CI, 0.56-1.15]). The risk of the primary composite renal outcome and the composite of cardiovascular death or hospitalization for heart failure were also consistently reduced in both the primary and secondary prevention groups (P for interaction >0.5 for each outcome). Conclusions: Canagliflozin significantly reduced major cardiovascular events and kidney failure in patients with type 2 diabetes mellitus and chronic kidney disease, including in participants who did not have previous cardiovascular disease
Improved imputation of low-frequency and rare variants using the UK10K haplotype reference panel
Imputing genotypes from reference panels created by whole-genome sequencing (WGS) provides a cost-effective strategy for augmenting the single-nucleotide polymorphism (SNP) content of genome-wide arrays. The UK10K Cohorts project has generated a data set of 3,781 whole genomes sequenced at low depth (average 7x), aiming to exhaustively characterize genetic variation down to 0.1% minor allele frequency in the British population. Here we demonstrate the value of this resource for improving imputation accuracy at rare and low-frequency variants in both a UK and an Italian population. We show that large increases in imputation accuracy can be achieved by re-phasing WGS reference panels after initial genotype calling. We also present a method for combining WGS panels to improve variant coverage and downstream imputation accuracy, which we illustrate by integrating 7,562 WGS haplotypes from the UK10K project with 2,184 haplotypes from the 1000 Genomes Project. Finally, we introduce a novel approximation that maintains speed without sacrificing imputation accuracy for rare variants
Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders
Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe